Book Description: Virtual goods is one of the most important topics for research, development, and implementation. It has influence on technology, business, and politics. While the discussion on legal aspects is highly political, new technologies are coming up almost daily, such as incentive communication, PDP networks, watermarks, fingerprints, usage control languages, etc. Finally, some business models adopt these new technologies such as the PotatoSystem (one of the basic models for the Virtual Goods Workshop since 2003); others try to utilize DRM in a more effective way, such as the Open Mobile Alliance, or i-Tunes. This new book presents the latest ideas in the field.

Modelling Social Networks as Authorised Domains with Decay pp. 183-195
(Nicholas Paul Sheppard, School of Computer Science and Software Engineering, University of Wollongong, Australia, Reihaneh Safavi-Naini, Department of Computer Science, University of Calgary School of Computer Science and Software Engineering, Canada)